1. The Field of the Invention
The present invention relates to the field of recycling. More particularly, the present invention relates to methods of collecting and processing recyclable plastic film waste through the formation of bales including both plastic and cardboard.
2. The Relevant Technology
The field of plastic recycling is increasingly important as the use of plastic wrap and plastic film bags permeate more and more aspects of retail sales as well as the shipping and packaging industry. For example, plastic shopping bags are well known to the general public as they are the predominant method for consumers to carry groceries and other purchased goods from a store. An even greater volume of plastic film, however, is generated for product packaging and distribution. For example, pallets of goods are frequently wrapped with large sheets of shrink wrap plastic to keep the content of the pallet from shifting or falling during transit. Another example is clothing distribution, wherein each garment is typically transported wrapped in its own plastic sleeve. Some estimates are that plastic bags on apparel account for over 60% of plastic waste at retail department stores.
With this proliferation of plastic wrap and plastic bags into the shipping and packaging industry, there is a need to recover this material out of the waste stream in an efficient and effective manner. Stores that aggressively collect and recycle waste plastic wrap and plastic bags separate from other garbage frequently save hundreds of dollars per month in the cost of trash hauling. Still, the storage, baling, shipping, and processing of the plastic is extremely inefficient under current methods.
At stores and distribution centers, for example, one conventional method of collecting plastic waste film for recycling is to stuff plastic into other large plastic bags and toss them somewhere in the facility in a haphazard fashion, for example on top of other bales or bins. For transportation, the bags are thrown into the back of a truck for transportation. Both of these methods are extremely inefficient uses of space.
Because of these challenges, the majority of plastic wrap and plastic bags are disposed of as waste. Not only does this add to pollution and more quickly fill landfills, but the plastic film fills on-site trash receptacles very quickly. Because waste is typically paid for by volume, i.e. the number of waste containers hauled off, the large volume of plastic film that is disposed of in on-site trash receptacles represent a significant cost. In addition, waste plastic film has a recycling value that is unrealized when the plastic film is disposed of in garbage.
Despite the challenges in collecting recyclable plastic film, uses for recyclable plastic are quickly expanding. For example, recycled plastic is now used in plastic garbage can liners, landfill liners, agricultural film, and composite lumber products for picnic tables, park benches, porches, and walkways where rot-resistant wood-like products are desired. Shipping containers, carpet materials, and hard plastic containers are also more and more frequently made with recycled plastic film. This increased demand for products made from recycled plastic is fueling an increased demand for the collection of recyclable plastic.
In addition, recent increases in the cost of raw petroleum have led to a dramatic increase in the cost of plastics for plastic products. As a result, the per pound value of collected recyclable plastic has also increased dramatically. This adds to the demand for the collection of recyclable plastic.
Nevertheless, the volume of plastic that is collected for recycling remains considerably lower than is feasible. One key imitation on the use of recyclable plastic is that plastic film is difficult and costly to collect. For example, consumers using small plastic bags rarely return them to a source whereby they can be recycled. In addition, shrink wrapped plastic and garment bags at department stores are often discarded rather than collected. In particular, garment bags and shrink wrapped plastic at department stores and warehouse stores are often discarded because the volume of space required to store all the plastic accumulated within the store becomes too expensive to dedicate to that purpose. Although there are feasible methods for collecting plastic film, such as dedicated plastic compactors and balers, these devices are too expensive and the volume of space that must be dedicated to storing precompacted plastic is usually impractical for most businesses.
By analogy, efforts at recycling cardboard have been much more successful. Cardboard recycling is performed at retailers, for example, by using large cardboard balers to compact waste cardboard and form the waste cardboard into bales for storage and transportation to cardboard recycling facilities. Cardboard balers are generally not used for plastic recycling, however, because they are much too large for the volume of plastic that is dealt with. Cardboard balers are typically designed to form forty-eight inch tall bales. The amount of loose plastic it would take to form a forty-eight inch tall bale simply cannot be stored by most, if not all, retailers. As a result, unlike cardboard, for which there is an efficient recycling infrastructure, there is currently no effective method for collecting large volumes of recyclable plastic.
In addition, plastic and cardboard cannot be mixed for recycling. This is because they are completely different materials that are recycled by very different processes. There are also no efficient methods to separate plastic and cardboard since the value of either material does not justify the labor. For this reason, it is well known that the presence of plastic film in a cardboard bale leads to rejection of the entire bale such that it is discarded rather than recycled.
Accordingly, it would represent an advance in the art to provide systems and methods to more efficiently and less expensively collect and process recyclable plastic for use in downstream recycling processes.